Puma Biotechnology announced that the FDA approved Nerlynx (neratinib) for the extended adjuvant treatment of adults with early-stage HER2-overexpressed/amplified breast cancer, following adjuvant Herceptin (trastuzumab)-based therapy. The company said it expects the once-daily oral tyrosine kinase inhibitor to become commercially available in September.

In May, an FDA advisory panel voted 12-4 that the benefits of Nerlynx for the extended adjuvant treatment of HER2-positive early-stage breast cancer outweighed the drug's risks. However, panellists at the time suggested that the compound, formerly known as PB272, should be restricted to patients who have received Roche's Herceptin within the past two years.

According to Puma Biotechnology, the FDA's approval was based on data from the Phase III ExteNET trial, which demonstrated that after two years of follow-up, invasive disease-free survival was 94.2 percent in patients treated with Nerlynx compared with 91.9 percent in those receiving placebo. In the study, the most common adverse reaction leading to discontinuation was diarrhoea, which was observed in 16.8 percent of patients treated with Nerlynx. The FDA noted that patients should be given loperamide for the first 56 days of treatment with Puma Biotechnology's drug and as needed thereafter to help manage diarrhoea.

A marketing application for Nerlynx is also under review by the European Medicines Agency.